foreign policy. >> reporter: the younger brother told the fbi that he and his brother were inspired by the anti-u.s. internet preaching of the radical cleric anwar al awlaki. even though the american born al qaeda figure was killed in a -- more than a year and a half ago, his words still have power. here condemning the u.s. actions in iraq and afghanistan, which the younger brother said, became their motivation to attack. >> we have chosen the path of war in order to defend ourselves from your oppression. >> reporter: the elder brother tamerlan had another favorite speaker. a chechen rebel leader who's video tamerlan posted online. here the leader threatens death to anyone who helps the infidels. he was killed by the russians last year. and it was on the internet, dzhokhar told fbi agents, that they learned how to make a bomb with a pressure cooker all found from an al qaeda online magazine. >> it suggests people are getting smarter about building easily manufactured bombs and targeting the united states. >> reporter: in russia today, the mother of the brothers tsarnaev, who first enco